Advances in Contact Angle, Wettability and Adhesion, Volume 2 E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Serie: Adhesion and Adhesives - Fundamental and Applied Aspects
• Sprache: Englisch

Seitenzahl: 634

Veröffentlichungsjahr: 2015

Beschreibung

This book is the second volume in the series "Contact Angle, Wettability and Adhesion." The premier volume was published in 2013. Even a cursory glance at the literature show that in recent years the interest in understanding and controlling wetting behavior has grown exponentially. Currently, there is tremendous research activity in rendering surfaces superhydrophobic, superhydrophilic, superoleophobic, superoleophilic, omniphobic and omniphilic because of their applications in many technologically important fields. Also the durability or robustness of materials with such super" characteristics is extremely significant, as well as the utilization of "green" (biobased) materials to obtain such surfaces. This book containing 19 articles reflects more recent developments in certain areas covered in its predecessor volume as well as it includes some topics which were not covered before. Concomitantly, this book provides a medium to keep abreast of the latest research activity and developments in the arena of contact angle, wettability and adhesion. The topics discussed include: Understanding of wetting hysteresis; fabrication of superhydrophobic materials; plasma treatment to achieve superhydrophilic surfaces; highly liquid repellent textiles; modification of paper surfaces to control liquid wetting and adhesion; Cheerios effect and its control; engineering materials with superwettability; laser ablation to create micro/nano-patterned surfaces; liquid repellent amorphous carbon nanoparticle networks; mechanical durability of liquid repellent surfaces; wetting of solid walls and spontaneous capillary flow; relationship between roughness and oleophilicity; superhydrophobic and superoleophobic green materials; computational analysis of wetting on hydrophobic surfaces: application to self-cleaning mechanisms; bubble adhesion to superhydrophilic surfaces; surface free energy of superhydrophobic materials; and role of surface free energy in pharmaceutical tablet tensile strength.

Leseprobe

Contents

Cover

Half Title page

Title page

Copyright page

Preface

Part 1: Fundamental and General Aspects

Chapter 1: Wetting of Solid Walls and Spontaneous Capillary Flow

1.1 Introduction: Capillary Flows and Contact Angles

1.2 A General Condition for Spontaneous Capillary Flow (SCF)

1.3 The Dynamics of SCF

1.4 Conclusion

References

Chapter 2: A Review of “Ordered Water Monolayer That Does Not Completely Wet Water” at Room Temperature

2.1 Introduction

2.2 “Ordered Water Monolayer that Does Not Completely Wet Water” at Room Temperature

2.3 Effect of Surface Point Defects on the Ordered Water Monolayer

2.4 Thermal Properties of Ordered Water Monolayer

2.5 Simulation or Experimental Observations on the Phenomenon of Water Droplets on Water Monolayers on Real Solid Surfaces at Room Temperature

2.6 “Ordered Ethanol Monolayer that does not Completely Wet Ethanol” at Room Temperature

2.7 Discussion

2.8 Summary

Acknowledgements

References

Chapter 3: Cheerios Effect and its Control by Contact Angle Modulation

3.1 Introduction

3.2 Theoretical Models

3.3 Control of Cheerios Effect

3.4 Concluding Remarks and Outlook

Acknowledgement

References

Chapter 4: Recent Mathematical Analysis of Contact Angle Hysteresis

4.1 Introduction

4.2 The Physical Principle and Mathematical Method

4.3 The Wenzel’s and Cassie’s Equations

4.4 The Modified Cassie Equation

4.5 Contact Angle Hysteresis

4.6 Conclusion and Outlook

Acknowledgments

References

Chapter 5: Computational Analysis of Wetting on Hydrophobic Surfaces: Application to Self-Cleaning Mechanisms

5.1 Introduction

5.2 Basic Relations in Differential Geometry

5.3 System Model

5.4 Governing Equations

5.5 Force Analysis

5.6 Results and Discussion

5.7 Conclusions

Acknowledgement

References

Chapter 6: Bubble Adhesion to Superhydrophilic Surfaces

6.1 Introduction

6.2 Theoretical Models

6.3 Experimental

6.4 Results and Discussion

6.5 Conclusions

Acknowledgement

References

Chapter 7: Relationship Between the Roughness and Oleophilicity of Functional Surfaces

7.1 Introduction

7.2 Basics and Experimental

7.3 Results and Discussion

7.4 Summary

Acknowledgements

References

Chapter 8: Liquid Repellent Amorphous Carbon Nanoparticle Networks

8.1 Introduction

8.2 Templates for Liquid Repellent Surfaces

8.3 Synthesis Without Flames

8.4 Synthesis by Combustion of Terpenoids

8.5 Amorphous Carbon Networks on 3-D Porous Materials for Liquid Filtration

8.6 Towards Robust Carbonaceous Films on Micro-textured Polymer Surfaces

8.7 Conclusions

References

Chapter 9: Recent Progress in Evaluating Mechanical Durability of Liquid Repellent Surfaces

9.1 Introduction

9.2 Durability to Tangential Shear

9.3 Durability to Dynamic Impact

9.4 Durability under Vertical Compression/Expansion

9.5 Wear in Liquid Baths

9.6 Inherently Durable Liquid Repellent Materials

9.7 Future Directions for Investigating Mechanical Durability

References

Chapter 10: Superhydrophobic and Superoleophobic Biobased Materials

10.1 Introduction

10.2 Advances in Liquid Repellent Cellulose Fiber Networks

10.3 Liquid Repellent Materials: Cellulose Derivatives

10.4 Liquid Repellent Thermoplastic Starch and Biopolyesters

10.5 Conclusions

References

Part 2: Wettability Modification

Chapter 11: Laser Ablated Micro/Nano-Patterned Superhydrophobic Stainless Steel Substrates

11.1 Introduction

11.2 Materials and Experimental Methods

11.3 Experimental Details

11.4 Results and Discussion

11.5 Conclusions

Acknowledgement

References

Chapter 12: RF Plasma Treatment of Neptune Grass (Posidonia oceanica): A Facile Method to Achieve Superhydrophilic Surfaces for Dye Adsorption from Aqueous Solutions

12.1 Introduction

12.2 Experimental Details

12.3 Results and Discussion

12.4 Conclusions

References

Chapter 13: Highly Liquid Repellent Technical Textiles Obtained by Means of Combined Photo-chemical and Laser Surface Modifications

13.1 Introduction

13.2 Background of the Conceptual Approach

13.3 Application of Combined Laser and Photochemical Modifications to Technical Textiles

13.4 Summary

Acknowledgement

References

Chapter 14: Modification of Paper/Cellulose Surfaces to Control Liquid Wetting and Adhesion

14.1 Introduction

14.2 Plasma Processing

14.3 Sticky vs. Roll-off Superhydrophobic Surfaces

14.4 Local Wetting/Adhesion Control

14.5 Superamphiphobic/Superomniphobic Paper

14.6 Summary and Conclusions

Acknowledgments

References

Part 3: Surface Free Energy and Adhesion

Chapter 15: Surface Free Energy of Superhydrophobic Materials Obtained by Deposition of Polymeric Particles on Glass

List of Notations

15.1 Introduction

15.2 Experimental

15.3 Results and Discussion

15.4 Conclusions

References

Chapter 16: Tablet Tensile Strength: Role of Surface Free Energy

16.1 Introduction

16.2 Applicability of the Proposed Model to Pharmaceutical Materials

16.3 Discussion

16.4 Summary

Acknowledgements

References

Chapter 17: Why Test Inks Cannot Tell the Whole Truth About Surface Free Energy of Solids

17.1 Introduction

17.2 Background

17.3 Materials and Methods

17.4 Results and Interpretation

17.5 Advantages and Drawbacks of Contact Angle Measurement in Practice

17.6 Summary

References

Index

Advances in Contact Angle, Wettability and Adhesion

Scrivener Publishing 100 Cummings Center, Suite 541J Beverly, MA 01915-6106

Adhesion and Adhesives: Fundamental and Applied Aspects

The topics to be covered include, but not limited to, basic and theoretical aspects of adhesion; modeling of adhesion phenomena; mechanisms of adhesion; surface and interfacial analysis and characterization; unraveling of events at interfaces; characterization of interphases; adhesion of thin films and coatings; adhesion aspects in reinforced composites; formation, characterization and durability of adhesive joints; surface preparation methods; polymer surface modification; biological adhesion; particle adhesion; adhesion of metallized plastics; adhesion of diamond-like films; adhesion promoters; contact angle, wettability and adhesion; superhydrophobicity and superhydrophilicity. With regards to adhesives, the Series will include, but not limited to, green adhesives; novel and high-performance adhesives; and medical adhesive applications.

Series Editor: Dr. K.L. Mittal 1983 Route 52, P.O. Box 1280, Hopewell Junction, NY 12533, USA Email: [email protected]

Publishers at Scrivener Martin Scrivener([email protected]) Phillip Carmical ([email protected])

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Co-published by John Wiley & Sons, Inc. Hoboken, New Jersey, and Scrivener Publishing LLC, Salem, Massachusetts. Published simultaneously in Canada.

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Library of Congress Cataloging-in-Publication Data:

ISBN 978-1-119-11698-1

Preface

The express purpose of this book series, Advances in Contact Angle, Wettability and Adhesion, is to provide a continuous state-of-the-art critical look at the current knowledge and latest developments in the arena of contact angle, wettability and adhesion.

Some historical facts related to the primordial study and evolution of contact angles and wetting phenomena were described in the Preface to Volume 1. Here I would like to supplement that information by mentioning some other significant milestones in the same vein. First, it is interesting to note that the titans of science like Einstein, Schrödinger and Bohr—all Nobel Laureates—evinced keen interest in capillarity (related to contact angle) and devoted part of their research to this topic. Next, the discovery of electrocapillarity, which in essence signifies manipulation/modulation of wettability (contact angle) by application of electric field, is attributed to the seminal and trailblazing work of Gabriel Lippmann (Nobel Laureate for Physics 1908) as part of his Ph.D. thesis. Electrowetting (EW) or modern electrowetting EWOD (electrowetting on dielectric) was developed from the phenomenon of electrocapillarity investigated in detail by Lippmann. So Gabriel Lippmann can aptly be called the father of electrowetting. Since the discovery of electrocapillarity, the ability to manipulate properties at the phase boundary by applied electric field has been vigorously pursued. The high tempo of research in EW stems from the fact that EWOD can be employed for a broad range of applications involving manipulations of liquids and requiring miniaturization of system size and improving its effectiveness. Lab-on-a-chip is a prime example of the application of EWOD. Lab-on-a-chip has been used in biomedical and analytical devices. Next, the work of the College de France, Paris, a world-renowned research school headed by Pierre-Gilles de Gennes (Nobel Laureate in Physics 1991), deserves special mention for its tremendous contribution towards understanding and explaining wetting phenomena (dynamics of wetting). Therefore, one can see that five Nobel Laureates have contributed to and brought glamour to the fascinating field of contact angles and wetting phenomena.

These days there is an overwhelming interest in biomimetics. According to Wikipedia, biomimetics or biomimicry is the imitation of the models, systems and elements of Nature for the purpose of solving complex human problems. Nature is a great teacher and the old adage, “Nature does not waste time in making frivolous or useless things,” is dead true; in this context, the lotus leaf is a classic paradigm. Even a cursory look at the literature will evince that currently there is a proliferation of research activity in all facets/ramifications of contact angles and wetting phenomena, and all signals indicate that this accelerated pace will be maintained.

The 17 research and review chapters comprising this book are divided into three parts – Part 1: Fundamental and General Aspects; Part 2: Wettability Modification; and Part 3: Surface Free Energy and Adhesion. The topics covered include: wetting of solid walls and spontaneous capillary flow; “ordered water monolayer that does not completely wet water” at room temperaure; Cheerios effect and its control by contact angle modulation; mathematical analysis of contact angle hysteresis; computational analysis of wetting and application to self-cleaning mechanisms; bubble adhesion to superhydrophilic surfaces; relationship between the roughness and oleophilicity of surfaces; liquid repellent amorphous carbon nanoparticle networks; mechanical durability of liquid repellent surfaces; superhydrophobic and superoleophobic biobased materials; laser ablation to render stainless steel superhydrophobic; RF plasma treatment of Neptune grass (Posidonia oceanica) to achieve superhydrophilic surfaces; combined photochemical and laser surface modifications to achieve liquid repellent textile surfaces; modification of paper/cellulose to control liquid wetting and adhesion; surface free energy of superhydrophobic materials; role of surface free energy in pharmaceutical tablet strength; and why test inks cannot tell the whole truth about surface free energy of solids.

As for this volume, it is essentially based on the written accounts of papers presented at the Ninth International Symposium on Contact Angle, Wettability and Adhesion held at Lehigh University, Bethlehem, PA, on June 16–18, 2014, under the auspices of MST Conferences. It should be recorded for posterity that all manuscripts submitted for this book were rigorously peer reviewed, suitably revised (some twice or thrice) and properly edited before inclusion in this book. As a matter of fact, some manuscripts are not included as they did not pass muster. So this book is not a mere collection of unreviewed and unedited papers, rather it represents articles which have passed rigorous peer scrutiny. Concomitantly, these articles are of archival value and their standard is as high as any journal or even higher than many journals.

It is quite manifest from the topics covered that the 17 chapters written by top-notch researchers which comprise this book address many aspects and ramifications of contact angles and wettability. The book provides a commentary on the current research being actively pursued in this domain and summarizes the research results of many active researchers in this field. Yours truly hopes that anyone wishing to stay abreast of the latest developments and prospects within the purview of contact angle, wettability and adhesion will find this book of great interest and value. In essence, Volume 2 supplements the information consolidated in its predecessor, Volume 1. In closing, I hope the information presented in this volume will spur further research and will serve as the provenance for new ideas. As we learn more about the wettability behavior of surfaces, new and exciting application vistas will emerge. All signals indicate that the high tempo of research in this field will continue unabated.

Now it is my pleasant duty to thank all those who contributed in many different ways in bringing this book to fruition. First and foremost, I am beholden to the authors for their enthusiasm, cooperation and contribution, without which this book would not have seen the light of day. Second, I would like to profusely thank the reviewers for their time and efforts in providing invaluable comments and suggestions which definitely improved the quality of articles included in this book. The comments from peers are a prerequisite for maintaining the highest standards of any publication. Last, but not least, my sincere appreciation goes to Martin Scrivener, publisher, for his unwavering support of this project and for giving this book a body form.

Kash Mittal P.O. Box 1280 Hopewell Jct., NY 12533 E-mail: [email protected] May 28, 2015

Part 1

FUNDAMENTAL AND GENERAL ASPECTS

Chapter 1

Wetting of Solid Walls and Spontaneous Capillary Flow

Jean Berthier1,* and Kenneth A. Brakke2

1CEA-LETI, CEA/University Grenoble-Alpes, Department of Technology for Life Sciences and Health Care, Grenoble, France

2Department of Mathematics, Susquehanna University, Selinsgrove, PA, USA

*Corresponding author: [email protected]

Abstract

Spontaneous capillary flows are of great importance in space and biophysics. In space, the gravitational forces are negligible and capillary forces govern liquid motion. In modern biotechnology, the scale of fluidic systems is so small that gravity can be neglected in comparison to capillary forces. In this chapter, we first derive the condition for onset of spontaneous capillary flow in open or confined microchannels; then we present an analysis of the dynamics of the capillary flow that generalizes the Lucas-Washburn-Rideal law to channels of arbitrary section. Finally, we illustrate the theoretical approach by considering the case of suspended capillary microflows.

Keywords: Spontaneous capillary flow (SCF), Gibbs free energy, Lucas-Washburn-Rideal (LWR) law, suspended microflows

1.1 Introduction: Capillary Flows and Contact Angles

At the macroscale, capillary forces seldom have a noticeable effect on physical phenomena. The reason is that their magnitude is much smaller than that of the usual macroscopic forces, such as gravity. However, in two cases capillary forces may become important: in space where gravity is negligible, and at the micro and nano-scale. In this chapter, we focus on the role and effect of capillarity at the microscale for microflows. More specifically, the relation between the wetting of the walls and the capillary flow is investigated, first from a static or quasi-static point of view, and then from a dynamic point of view.

Biotechnology, biology and medicine are domains where capillarity is now widely used. Let us recall that in all these domains, the concepts of point-of-care (POC) and home care are of increasing interest [1-5]. These systems allow for self-testing and telemedicine. Three main types of tests are targeted: first, the search for metabolites—such as cholesterol, glucose, and thyroid hormones; second, the search for viral load—such as viruses and bacteria; and third, blood monitoring—such as the measure of INR (international normalized ratio), coagulation time, prothrombin (PR) time, or blood cell counts. Monitoring at home or at the doctor’s office is an important improvement for the patient: frequent testing, immediate response, no visit to the hospital, and monitoring by telemedicine or directly by the doctor. Such systems must be low-cost, easily portable, sensitive, and robust.

In these domains where biological and chemical targets are transported by liquids, capillary actuation of liquids does not require bulky pumps or syringes, or any auxiliary energy sources. The energy source for the flow is the surface energy of the microchannel walls. On the other hand, conventional forced flow laboratory systems require the help of bulky equipment, which is expensive and not portable.

By definition, a spontaneous capillary flow (SCF) occurs when a liquid volume is moved spontaneously by the effect of capillary forces—without the help of auxiliary devices such as pumps or syringes. Capillary systems can be either confined or open, i.e. the liquid moves inside a closed channel or in a channel partially open to the air. On the other hand, composite channels—sometimes partly open or with apertures—are increasingly used, and spontaneous capillary flow is a convenient method to move liquids in such geometries. Some examples of SCF are shown in Figure 1.1.

Figure 1.1 Different examples of spontaneous capillary flows (SCF) in open-surface microchannels (channels etched in silicon and coated by an SiO2 layer): (a) serial SCF; (b) parallel SCF; (c) parallel channels; (d) winding channels crossing wells; (e) filling of a cylindrical cavity; (f) capillary filaments in a cylindrical well; (g) capillary filaments in corners. Photographs by N. Villard, D. Gosselin and J. Berthier (CEA-Leti).

In this chapter, we first investigate the conditions for spontaneous capillary flow in open or confined microchannels, composite or not, and we show that a generalized Cassie angle governs the onset of SCF [6]. Then we present the dynamics of the capillary flow with a generalized Lucas-Washburn-Rideal expression for the flow velocity and travel distance [7-9]. Finally, we focus on the particular effect of precursor capillary filaments—sometimes called Concus-Finn filaments [10,11]—that sometimes exist in sharp corners, depending on the wettability of the walls.